Design And Implementation Of High Precision Clock Synchronization In Distributed Systems

Aiming at the problems of mutual independence and lack of unified space and time benchmarks among the test equipment among the network nodes in the distributed full trajectory test system for light weapons targets,the clock synchronization and triggering of the distributed network test system were studied,and the corresponding test system was built to achieve clock synchronization and triggering with fast synchronization speed,high synchronization accuracy,and stable operation.This article first analyzes and compares the existing clock synchronization technologies and related achievements and then selects the IEEE 1588 protocol to achieve clock synchronization.Then,according to the characteristics of the distributed testing system for light weapons targets,the main research content of this paper is to achieve clock synchronization and triggers in the distributed system and improve the speed,accuracy,and stability of synchronization.A technical analysis of high-precision clock synchronization and triggering in distributed systems is conducted,including the IEEE 1588 protocol delay request response mechanism and clock synchronization process in E2 E mode,the impact of network node local clock algorithms on clock synchronization accuracy,and clock synchronization accuracy under different influencing factors.The IEEE 1588 protocol is implemented in the network node synchronization trigger unit designed using the physical layer timestamp chip DP83640 and the master controller STM32F407;the local clock algorithm is optimized using amplitude-limiting average filtering,the adaptive PI algorithm,and Kalman filtering.The clock synchronization results of different algorithms are analyzed through experiments or simulations.The trigger management of network nodes in a distributed system is implemented through the design of second pulse output,trigger output,and trigger capture.In order to further improve clock synchronization accuracy,the impact of different factors on clock synchronization accuracy was explored from three perspectives: different crystal oscillators,different node switches,and different topologies.The optimal scheme for building a distributed network test system for light weapon targets was identified.An experimental platform was built to achieve high-precision clock synchronization for distributed systems,and two major aspects of clock synchronization and triggering were tested in the PTP domain using the built system,including the speed,accuracy,and stability of system clock synchronization;the timing of single-sequence trigger output and capture;and the timing of the same external signal trigger output and capture,etc.The experimental results show that a distributed test system that uses a temperaturecompensated crystal oscillator to provide clock signals,uses a switch that supports the PTP protocol and is configured to calculate the dwell time for E2 E TC,and uses a linear topology to connect network nodes can complete clock synchronization within 2 minutes,with synchronization accuracy stable at 40 ns for a long time.The trigger and capture functions of the system are intact,and the trigger accuracy is better than 1μs when the cable length is controlled within 200 m.The design of the system meets the technical specifications and operational requirements of distributed full ballistic testing of light weapons targets.